Association study between a novel single nucleotide polymorphism of the promoter region of the prostacyclin synthase gene and essential hypertension.

The purpose of this study was to investigate whether an association exists between the promoter region of the prostacyclin synthase gene and essential hypertension (EH). Using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method, we discovered a novel single nucleotide polymorphism (SNP), T-192G, in the 5'-flanking region. We performed an association study using the SNP in 200 patients and 200 controls. The allele frequency distribution in the two groups was not significantly different. Thus, this SNP in the PGIS gene is not associated with EH.     

Haplotype analysis of PPARγ C681G and intron CT variants

Background

There is strong evidence suggesting an association between the peroxisome-activated receptor γ (PPARγ) gene and multimetabolic disorders. The association of PPARγ genetic variants with essential hypertension (EH) has not yet been investigated. The aim of this study was to investigate the association between the PPARγ gene (C681G and intron CT) and EH, examining the polymorphism and haplotype in a Han Chinese population.

Methods

Participants were recruited within the framework of the PMMJS cohort population survey in an urban community of Jiangsu Province, China. Two single-nucleotide polymorphisms (SNPs) previously reported to be associated with multimetabolic disorders and the reasonable coverage of the PPARγ gene region were analyzed with TaqMan SNP genotyping assays.

Results

C681G and intron CT were significantly associated with an increased risk of EH both in the codominant model and the dominant model after adjusting for potential nongenetic risk factors. Analysis of the haplotype association revealed that the risk of EH was significantly increased among individuals carrying the GC (odds ratio, 95?% CI: 1.60, 1.21–2.11), CT (1.45, 1.03–2.11), and GT haplotypes (1.95, 1.17–3.23) compared with those carrying the CC haplotype.

Conclusion

The polymorphisms of C681G and intron CT were significantly associated with the risk of EH, and the GC, CT, and GT haplotypes established by C681G and intron CT are likely to be genetic markers of EH in the Han Chinese population.     

Haplotype analysis of the human renin gene and essential hypertension

The human renin gene is an attractive candidate for involvement in the underlying cause of essential hypertension (EH). Despite extensive examination, the relation between the renin gene and hypertension remains unclear. The aims of the present study were to discover new genetic markers of EH and to investigate the relations between polymorphisms of the renin gene and EH in the Japanese. Using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method, we isolated 3 novel variants of the renin gene; a single nucleotide polymorphism (SNP) in intron 4 (T+17int4G), a variable number of tandem repeats (VNTR) polymorphism in intron 7, and a missense mutation in exon 9 (G1051A). We performed an association study with these polymorphisms in 212 patients with EH and 209 age-matched normotensive (NT) subjects. The frequency of genotypes VNTR and T+17int4G did not differ significantly between the 2 groups, whereas the overall distribution of G1051A was significantly different between EH and NT. Haplotype analysis revealed that the overall distribution of haplotypes differed significantly between the EH and NT groups. PRA levels in patients with EH with the G/G genotype were significantly higher than in subjects with EH with G/A and A/A genotypes. These data suggest that the missense mutation in exon 9 may affect the enzymatic function of renin and consequently may be involved in the etiology of hypertension.     

Association of ACE gene A2350G and I/D polymorphisms with essential hypertension in the northernmost province of China

Angiotensin converting enzyme (ACE) gene, as a strong candidate gene for essential hypertension(EH), has been extensively studied. In this study, we carried out a population-based case-control study to explore whether ACE gene I/D and A2350G polymorphisms could consider to be risk factors for EH. A total of 2040 subjeces were recruited from Chinese Han in this study, out of which 1010 were cases and 1030 were normotensive individuals. ACE gene A2350G and I/D polymorphisms were amplified by polymerase chain reaction (PCR) and A2350G polymorphism was detected after restriction enzyme digestion with BstuI. Besides, we choosed 10% samples randomly sequencing to verify the accuracy of results. Genotype and allele frequencies distribution of I/D and A2350G in EH and control groups were significantly different. After grouped by sex or age, there were still statistical significances for two polymorphisms. In dominant and recessive model of A2350G, we found significant differences between two groups, respectively. For ACE I/D polymorphism, we observed that the existence of dramatical difference in dominant model between two groups, while in recessive model, marginally significant difference was found. Among the four haplotypes composed by ACE gene A2350G and I/D, haplotype G-D reached the statistical significance in two groups, and exhibited to be a risk factor for the development of EH, whose P < 0.001 and OR 95%CI = 1.639(1.435–1.872), while the other haplotypes were the protective factors and decreased the susceptibility to EH(P < 0.05). ACE gene A2350G and I/D polymorphisms were associated with increasing the risk of suffering from EH in the northernmost province of China individuals, with D allele and G allele individuals had a higher risk of EH(OR = 1.443, 95%CI = 1.273–1.636 and OR = 1.481, 95%CI = 1.303–1.684).     

Two medium-chain acyl-coenzyme A synthetase genes, SAH and MACS1, are associated with plasma high-density lipoprotein cholesterol levels, but they are not associated with essential hypertension

BACKGROUND AND OBJECTIVES: SAH has been proposed as a candidate gene for essential hypertension (EH) because elevated expression of SAH was observed in the kidneys of spontaneously hypertensive rats. Recently, a homology search of SAH in the human genome revealed the presence of the SAH gene family, which includes SAH, MACS1, MACS2, and MACS3. SAH and MACS1 are located within a 150-kb region on human chromosome 16p13.11. SAH and MACS1 are thought to function as acyl-coenzyme A synthetases, which are involved in fatty acid metabolism. In the present study, we analyzed six single nucleotide polymorphisms (SNPs) in the SAH and MACS1 genes in a Japanese population, and examined whether these SNPs contribute to EH and multiple risk factors. METHODS AND RESULTS: We performed association studies of six SNPs in 287 EH patients and 259 normotensive subjects. Multiple logistic linear regression analysis revealed that the allele frequencies of these six SNPs in SAH and MACS1 genes were not significantly different between EH patients and normotensives. SNP in exon 8 of the A/G polymorphism of the MACS1 gene and the G/T SNP in intron 3 of the SAH gene were associated with plasma levels of plasma high-density lipoprotein cholesterol. CONCLUSIONS: SNPs in the MACS1 and SAH genes contribute to plasma levels of high-density lipoprotein cholesterol.     

血管紧张素Ⅱ 1型受体基因573T〉C和1166A〉C多态性与新疆哈萨克族高血压的关系

目的:研究血管紧张素Ⅱ 1型受体(AT1R)基因573T>C和1166A>C多态性与新疆哈萨克族原发性高血压(EH)的关系.方法:采用病例-对照研究随机选取新疆哈萨克族牧民EH患者(EH组)194例,正常血压者(对照组)115例,采用聚合酶链反应和限制性片段长度多态性技术检测AT1R基因573T>C和1166A>C多态性,用最大似然法估计两位点单体型频率.结果:AT1R基因573T>C多态性在EH组中T、C等位基因频率分别为0.799,0.201,对照组中T、C等位基因频率分别为0.713和0.287,EH组T等位基因频率高于对照组(P<0.05).1166A>C位点仅在EH组检测到1例CC基因型,A、C 2种等位基因和基因型频率在2组间分布差异无统计学意义(均P>0.05).573T>C和1166A>C间未检测到连锁不平衡.T573-A1166组成的单体型频率最高,占70.4%,其次是C573-A1166,为17.1%.2组间单体型分布差异无统计学意义(P>0.05).不同单体型对EH的影响差异无统计学意义(均P>0.05).结论:AT1R基因573T>C的T等位基因和TT及TC基因型是新疆哈萨克族EH可能的易感因素,而573T>C和1166A>C组成的单体型可能与新疆哈萨克族EH无关.     

Lipoprotein lipase gene polymorphisms and blood pressure levels in the Northern Chinese Han population.

The lipoprotein lipase (LPL) gene has been investigated extensively in linkage studies and in studies of its association with lipid profiles and coronary artery disease (CAD), and this gene has also been reported to have an association with hypertension. In our previous linkage study on 148 Chinese hypertensive families, the regions at or near the LPL gene were found to be associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP). Thus the LPL gene is a logical candidate gene for involvement in the underlying cause of essential hypertension (EH). In the present study, we identified 22 sequence variants by directly sequencing 10 exons and flanking regions of the LPL gene, and investigated the occurrence of 3 of these variants, IVS4-214C>T, 7754C>A and S447X, in a case-control study including 501 normotensive (NT) subjects and 497 EH subjects. In males, the frequencies of the genotypes of each of the 3 variants did not differ significantly between the NT and EH groups. Among the EH group in females, ANCOVA revealed no significant difference in blood pressure levels according to the 7754C>A genotype. However, in female, the distribution of the 7754C>A genotype and the frequency of the A allele of 7754C>A differed significantly between the NT and EH groups (p=0.032 and p=0.027, respectively) with 0.78 (95% confidence interval (CI): 0.56 to 1.07; p=0.12) of odds ratio for the A allele. Moreover, haplotype analysis revealed that T-A-C and T-C-G haplotypes (in the order of IVS4-214C>T, 7754C>A and S447X) were statistically more frequent in the NT group than in the EH group in females and males, respectively. Our indivisual single nucleotide polymorphism (SNP) analysis did not provide substantial evidence of an association between polymorphisms in the LPL gene and hypertension status and/or blood pressure levels in this cohort, but the more powerful haplotypes analysis suggested an association between the LPL gene and hypertension.     

新疆汉族和哈萨克族人群内皮型一氧化氮合酶基因T786C和G894T多态性与原发性高血压的相关分析

目的探讨新疆汉族和哈萨克族内皮型一氧化氮合酶基因G894T、T786C多态性与原发性高血压的相关性。方法选取新疆塔城地区哈萨克族高血压患者363人和正常血压者370人,选取汉族高血压患者346人,正常血压者385人,运用多重单碱基延伸分型技术进行内皮型一氧化氮合酶基因G894T、T786C多态性分析,阐明两民族基因型、等位基因频率分布、连锁不平衡模式及构建的单体型与原发性高血压的相关性。结果超重、肥胖、甘油三酯异常及年龄51岁以上是两民族患高血压的共同相关危险因素。总人群、原发性高血压组及正常血压组中两民族内皮型一氧化氮合酶基因G894T、T786C位点等位基因频率分布差异均有统计学意义(P<0.05),两位点间不存在强连锁不平衡。汉族和哈萨克族人群内皮型一氧化氮合酶基因两位点共构成4种单体型:GT(75.3%和79.6%)、GC(10.8%和10.5%)、TT(5.7%和9.8%)及TC(8.2%和0.1%)。两民族单体型频率分布最高为GT,汉族和哈萨克族人群单体型频率分布最低分别是TC、TT,且两民族间单体型GT、TT、TC频率分布差异有统计学意义(P<0.05)。结论新疆汉族和哈萨克族人群内皮型一氧化氮合酶基因G894T、T786C位点多态可能与原发性高血压不相关。     

转化生长因子β_1基因标签单核苷酸多态性与新疆汉族原发性高血压相关性研究

目的 研究转化生长因子β_1(TGF-β_1)基因标签单核苷酸多态(tSNP)及血浆水平与新疆汉族原发性高血压(EH)的关系,阐明连锁不平衡(LD)模式以及单体型分布特征.方法 采用整群抽取随机抽样的方式,以新疆沙湾县732例汉族人(EH组365例,对照组367例)为研究对象,进行流行病学调查和临床检查,并采集血样.用双抗体夹心法(ELISA试剂盒)测量TGF-β_1血浆浓度.SNaPshot方法进行基因分型.结果 (1)TGF-β_1基因rs11466345位点等位基因A、G在EH组和对照组中分布频率分别为69.7%、30.3%、74.4%、25.6%,EH组G等位基因频率高于对照组(x2=3.949,P=0.047),G等位基因患病风险为A等位基因1.261倍(95%CI 1.003～1.585,P=0.047),其他tSNP基因型及等位基因频率在EH组和对照组分布差异元统计学意义(P>0.05).(2)除m11466345位点外,其他tSNP位点间存在强LD,其构成的单体型频率在EH及对照组中分布差异无统计学意义(P>0.05).(3)TGF-β_1基因tSNP在EH组与对照组各基因型和等位基因之间TGF-β_1血浆水平差异无统计学意义(P>0.05).结论 TGF-β_1基因rs 11466345G等位基因可能是新疆汉族EH的遗传易感基因,其他tSNP可能与该民族EH不相关,除rs11466345位点外,其余tSNP位点间存在强LD,其构成的单体型与EH无关;在新疆汉族人群中TGF-β_1基因tSNP与TGF-β_1血浆水平不相关.     

血管紧张素Ⅱ 1型受体基因单核苷酸多态性与原发性高血压和冠心病的相关研究

目的研究血管紧张素Ⅱ1型受体基因（AT1）单核苷酸多态性（SNP）与华东地区汉族人原发性高血压和冠心病的相关性。方法对AT1基因的启动子区、5’非翻译区、外显子及邻近内含子和3’非翻译区设计引物进行分段扩增,采用直接测序法在20个随机样本中检测AT1基因的SNP,选择所发现的SNP在213例单纯高血压、171例高血压合并冠心病和200例正常对照中进行基因分型,以期探讨ATl基因在原发性高血压和冠心病发病中的作用。结果共检出8个SNP,其中6个在启动子区,1个在编码区,1个在3’非翻译区,分别对SNP6（A-153G）、SNP7（T573C）和SNP8（A1166C）行基因分型,显示位于启动子-153G等位基因在原发性高血压合并冠心病组中的频率是17．8％,在对照组中是11．5％（P〈0．05）,而T573C和A1166C多态则未显示有统计学意义。结论血管紧张素Ⅱ1型受体基因启动子-153位A被G替代可能与华东汉族人原发性高血压患者合并冠心病相关。     

A common missense single nucleotide polymorphism in the E-selectin gene is significantly associated with essential hypertension in the Han population but only weakly associated in the Uygur population

Experimental and clinical observations suggest that E-selectin could have an important role in essential hypertension (EH), but the relationship between common E-selectin variants and EH has not been extensively studied in the Chinese population. In this study, we explored the association between two common variants in the E-selectin gene (rs5361A/C and rs5355C/T) and EH in the Uygur, Kazakh and Han populations in the Xinjiang area. A case-control study was conducted to explore the association between these two single-nucleotide polymorphisms and EH in a large sample size, including 941 EH subjects (309 Uygur, 264 Kazakh and 368 Han individuals) and 924 control subjects (300 Uygur, 275 Kazakh and 349 Han individuals). Univariate analysis showed that the rs5361 A/C polymorphism was significantly associated with EH in the Uygur (P=0.002) and Han (P=3.6 × 10(-7)) populations. The CC genotype of this SNP was present only in patients with EH in all of the three nationalities studied. Han individuals who carry the CC genotype of rs5361 were more susceptible to EH, according to the dominant models (P=1.13 × 10(-4), odds ratio=3.812, 95% confidence interval: 1.685-7.792), but there was no association of genotype with EH for the other ethnicities. No significant difference in rs5355 C/T polymorphism rate was found between the EH and control groups. Our results indicate that the common variant rs5361 is strongly associated with EH in Han individuals and weakly associated in Uygur individuals. The CC genotype of rs5361 might be an independent risk factor for EH among Uygur, Kazakh and Han individuals in the Xinjiang area.     

Prostacyclin synthase gene: genetic polymorphisms and prevention of some cardiovascular diseases

Prostacyclin (PGI2) inhibits platelet aggregation and vasoconstriction. Prostacyclin synthase (PGIS), a catalyst of PGI2 synthesis from prostaglandin H2, is widely distributed and predominantly found in vascular endothelial and smooth muscle cells. The PGIS gene is localized to 20q13.11-13, and a candidate gene for cardiovascular disease. We discovered mutations and polymorphisms in this gene and reported that they were associated with essential hypertension, myocardial infarction and cerebral infarction. These results suggest that PGI2 function depends on the different alleles of the PGIS gene and that they may influence the risk of cardiovascular diseases. Thus, individualized management strategies, such as administration of PGI2 analog, could be selected for variants of this gene to help prevent the development of cardiovascular diseases.     

Association between ALOX5AP gene polymorphisms and coronary artery disease in the Han population of North China

Objectives Recent evidence have implicated specific gene polymorphisms of arachidonate 5-lipoxygenase-activating protein(ALOX5AP),and 2 at-risk haplotypes (HapA,HapB ) in myocardial infarction(MI) and stroke, whereas other studies have been conflicting and to date,no data concerning coronary artery disease(CAD) are available in the Han population of North China.The aim of the present study was to investigate the possible associations between the variants of ALOX5AP gene and susceptibility to CAD in the Han population of North China.Methods We sequenced the promoter,all of the exons,splite site region and 3’untranslated region of ALOX5AP gene,and 7 single nucleotide polymorphisms(SNPs) were found.Three(-1340T/G,+ 8733T/C,+20616G/C) of these polymorphisms were evaluated in 656 patients with angiographically proven CAD and 678 controls with normal coronary angiograms using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) assay.Allelic,genotypic and haplo-typic association testing were performed using Shesis and Phase version 2.1 software package.Multiple logistic regression was used to control for the presence of vascular risk factors.Results While none of the single nucleotide polymorphism (SNP) was found to be associated with CAD risk individually,there was an association with the 3 SNP haplo-types. We identified a protective haplotype -1340T,+8733C and +20616G(Bonferroni-corrected P=0.000002984,OR = 0.623,95%CI=0.519-0.748) and a risk haplotype -1340G, +8733C and +20616G(Bonferroni-corrected P =0.000018, OR=1.728,95%CI=1.375-2.171).The frequencies of all alleles were in Hardy |= Weinberg equilibrium.Conclusions Our data suggest that unique haplotype combinations in the ALOX5AP gene may play a role in the etiology of CAD.     

GNB3 gene C825T and ACE gene I/D polymorphisms in essential hypertension in a Kazakh genetic isolate

The Kazakh inhabitants living in Barkol pasture of northeast China belong to a genetic isolate characterized by ethnically homogeneous and a communal pastoral lifestyle. To investigate whether the polymorphisms in the G-protein beta-3 subunit (GNB3) gene and angiotensin-converting enzyme (ACE) gene are associated with essential hypertension (EH), we carried out a case-control study of 290 hypertensive subjects and 244 normotensive (NT) controls randomly selected from Kazakh populations of Barkol. A previous medical history of diabetes and hypertension, and body mass index (BMI) was recorded. Plasma glucose, triglyceride, and cholesterol were measured. The insertion/deletion (I/D) polymorphism of the ACE gene and the C825T polymorphism of the GNB3 gene were determined by the polymerase chain reaction (PCR) technique. The distributions of genotypes and alleles for the two polymorphisms did not differ significantly between the case and control populations, and odds ratio of EH related to the ACE gene D allele and GNB3 gene T allele was not significantly different from 1.0. Logistic regression analysis shows the variation at the GNB3 and ACE did not have any statistically significant synergistic effect on blood pressure (BP). Stratification of NT and untreated hypertensives according to I/D polymorphism of ACE gene and C825T polymorphism of GNB3 gene disclosed no significant difference across genotypes with respect to BMI, glucose, triglyceride, cholesterol, systolic and diastolic BP. In conclusion, the polymorphisms in the GNB3 gene and ACE gene, solely or combined, did not confer a significantly increased risk for the development of EH in the Kazakh isolate of northeast China.     

A novel single-nucleotide polymorphism at the 5'-flanking region of SAA1 associated with risk of type AA amyloidosis secondary to rheumatoid arthritis.

OBJECTIVE: To address whether the gamma haplotype at exon 3 of the SAA1 gene is directly associated with type AA amyloidosis or is merely in linkage with an unknown polymorphism that is primarily associated with disease risk, we examined the SAA1 gene for new polymorphisms. METHODS: We analyzed DNA samples from 44 rheumatoid arthritis (RA) patients with AA amyloidosis (amyloid group), 55 RA patients without AA amyloidosis (RA group), and 58 non-RA healthy subjects (non-RA group). We also examined DNA samples from 50 Caucasians to compare linkage disequilibrium relationships involving SAA1 region polymorphisms between Japanese and Caucasoid populations. RESULTS: We observed 3 novel single-nucleotide polymorphisms (SNPs) in the 5'-flanking region of SAA1: -61C/G, -13T/C, and -2G/A. Comparison of allele frequencies and ratios of individuals with particular alleles between the study groups revealed statistically significant differences between the amyloid and RA groups and between the amyloid and non-RA groups. Statistical analysis revealed that the -13T/C SNP was strongly associated with AA amyloidosis. In addition, we found tight linkage between the -13T allele and the alpha haplotype, rather than the beta haplotype, at exon 3 in the Caucasoid population, while -13T was closely linked to the gamma and beta haplotypes, rather than the alpha haplotype, in the Japanese population. Since the linkage disequilibrium relationship was reversed between the Japanese and Caucasoid populations, different exon 3 haplotypes of SAA1 are found to be associated with the risk of AA amyloidosis in different ethnic groups. CONCLUSION: Our data suggest that the SAA1 -13T allele, rather than SAA1 exon 3 haplotypes, is primarily associated with AA amyloidosis risk.     

Associations of CYP4A11 gene–gene and gene–smoking interactions with essential hypertension in the male eastern Chinese Han population

Objectives: The aim of this study was to investigate the impact of CYP4A11 single-nucleotide polymorphisms (SNP), additional gene–gene and gene–environment interactions on essential hypertension (EH) risk. Methods: A total of 1648 participants (788 males, 860 females), with a mean age of 56.1 ± 14.1 years old, were selected, including 820 EH patients and 828 normotension subjects. Logistic regression was performed to investigate association of SNPs within CYP4A11 gene with high DBP, high SBP and EH risk, and generalized multifactor dimensionality reduction (GMDR) was used to analyze the gene–gene interaction and gene–smoking interaction. Results: Logistic regression analysis showed that EH risk was significantly higher in carriers of C allele of the rs1126742 polymorphism than those with TT genotype (TC+CC versus TT, adjusted OR (95%CI) = 1.56 (1.24–1.91). In addition, we also found that EH risk was also significantly higher in carriers of G allele of the rs3890011polymorphism than those with CC genotype (CG+ GG versus CC, adjusted OR (95%CI) = 1.31 (1.15–2.03). GMDR analysis indicated a potential gene–gene interaction between rs1126742 and rs3890011 and a gene–environment interaction between rs1126742 and smoking. We found that subjects with TC or CC of rs1126742 and CG or GG of rs3890011genotype have the highest EH risk, OR (95%CI) was 2.52 (1.28–3.57). Smokers with TC or CC of rs1126742 genotype have the highest EH risk, OR (95%CI) was 2.20 (1.28–3.40). Conclusions: Gene–gene interaction between rs1126742 and rs3890011 and gene–environment interaction between rs1126742 and smoking were associated with increased EH risk.     

Haplotype of the angiotensinogen gene is associated with coronary heart disease in familial hypercholesterolemia

OBJECTIVE: Familial hypercholesterolemia is characterized by high plasma low-density lipoprotein cholesterol levels and premature coronary heart disease. Despite the monogenetic origin of familial hypercholesterolemia, the incidence of coronary heart disease varies considerably among patients, which is only partly explained by classical risk factors. Hypertension is an important risk factor for coronary heart disease that is associated with angiotensinogen levels. Therefore, we analyzed the angiotensinogen gene as a modifier gene for coronary heart disease risk in patients with familial hypercholesterolemia. METHODS: In a cohort of 1785 familial hypercholesterolemia patients, we reconstructed five frequent haplotypes of the angiotensinogen gene, based on four polymorphisms. The five haplotypes cover approximately 98% of the genetic diversity accounted for by these four polymorphisms. The associations between the haplotypes and coronary heart disease were analyzed with the haplo.stats program, adjusted for age, sex and smoking. RESULTS: Patients homozygous for the C allele of the 4072 T>C polymorphism had a 34% increased coronary heart disease risk (P = 0.017) compared to patients homozygous for the T allele. Haplotype H3, consisting of the minor allele of the 4072T>C polymorphism and the major alleles of the other polymorphisms, had a frequency of 15% and was associated with a 45% increased coronary heart disease risk (P = 0.006) compared to the wild-type haplotype H1. CONCLUSIONS: We conclude that genetic variation in the angiotensinogen gene contributes to coronary heart disease risk in patients with familial hypercholesterolemia.     

Role of genetic polymorphisms in myocardial infarction at young age

Acute myocardial infarction (AMI) in young adult presents a typical pattern of risk factors, clinical, angiographic and prognostic characteristics. In the last years we demonstrated that hemorheological profile is altered in these patients in a persistent way and independently of the number of risk factors and of the extent of coronary lesions. Thus, the hyperviscosity syndrome following AMI could be considered an intrinsic characteristic of these patients. Consequently it is possible to hypothesise the presence of a genetic background at the origin of this predisposition. If this background is able to influence the risk of ischemic heart disease, this should be particularly evident in young subjects. Since inflammatory mechanisms play a central role in mediating all phases of atherosclerosis, genes encoding for inflammatory or anti-inflammatory molecules are candidates for the risk of developing atherosclerosis. As atherosclerosis is the first cause of mortality in Western countries and if pro-inflammatory genotypes contribute to risk of coronary heart disease, alleles associated to disease susceptibility should not be included in the genetic background favouring longevity: People genetically predisposed to a weak inflammatory activity have fewer chances to develop cardiovascular disease and, therefore, have better chance for a long-life. According to this hypothesis, we studied in our population of young patients with AMI, the distribution of some polymorphisms influencing a inflammation and found an higher prevalence of pro-inflammatory polymorphisms (SNP A2080G of pyrin gene, SNP Gly670Arg of PECAM gene, C1019T of Cx 37 gene, SNP G1059C of PCR gene) and a lower prevalence of anti-inflammatory polymorphisms (Asp299Gly of TLR4 gene, SNP -1082 G/A of IL10 gene, CCR5Δ32). Results of these studies show that early myocardial infarction could be associated with a genetic predisposition to an intense inflammatory response, associated also to an hyperviscosity syndrome.     

Variation of the factor VII gene and ischemic heart disease in Japanese subjects

BACKGROUND: Polymorphisms of the 5' region (5'FT), an intronic mutation (IVS7), and the 353Arg-Gln (R353Q) substitution of the factor VII gene have been reported to be associated with the plasma level of factor VII. Greater than normal levels of factor VII have also been reported to be associated with atherothrombotic events. However, the significance of factor VII gene polymorphism in the pathogenesis of ischemic heart diseases (IHD) has not been confirmed. OBJECTIVE: To determine whether these three factor VII gene polymorphisms are associated with levels of factor VII in Japanese subjects, and whether these three polymorphisms of the factor VII gene are associated with the risk of myocardial infarction. METHODS: We studied three polymorphisms of the factor VII gene, 5'FT, IVS7, and R353Q polymorphisms, for 493 Japanese subjects consisting of 285 subjects without clinical evidence of ischemic heart disease (non-IHD group) and 208 myocardial infarction patients (myocardial infarction group). We also assessed the plasma levels of factor VII antigen (FVIIag) in 103 subjects in the non-IHD group. RESULTS: Multiple regression analysis revealed that the level of FVIIag was significantly associated with age, body mass index, cholesterol level and a polymorphism of the factor VII gene (5'FT). Logistic analysis of 493 subjects revealed that cholesterol level [P = 0.0036, odds ratio 1.010, 95% confidence interval (CI) 1.003-1.017], smoking (P = 0.0001, odds ratio 5.522, (95% CI 2.684-11.364) and diabetes mellitus (P = 0.0001, odds ratio 6.450, (95% CI 2.953-14.088) were risk factors for myocardial infarction. However, the three polymorphisms of factor VII gene were not associated with risk of myocardial infarction. CONCLUSION: The polymorphisms of the factor VII gene influenced the levels of factor VII but were not significantly associated with risk of myocardial infarction in Japanese subjects.     

A novel variable number of tandem repeat polymorphism of the renin gene and essential hypertension.

The aims of the present study were to find new genetic markers of essential hypertension (EH) and to investigate relationships between EH and polymorphisms of the renin gene. Using single strand conformation polymorphism, we discovered a new variable number of tandem repeat (VNTR) polymorphism in intron 7 that is 18 bp upstream from the boundary with exon 8. Nucleotide sequencing revealed that this VNTR polymorphism is a tandem repeat of the 4-nucleotide sequence TCTG. There were 6 alleles of this VNTR polymorphism, ranging from 7 repeats to 12 repeats. We analyzed the association between EH and this VNTR polymorphism. There was no significant difference in the overall distribution of this VNTR polymorphism between the EH and normotensive subjects. In summary, we discovered a novel VNTR polymorphism in the renin gene, and this polymorphism was not associated with EH.